Improvement in fire-alarm telegraph apparatus



I 2 Sheets-Sheet 1. 1 N GAMEWELL.

Signal Box for Electra-Magnetic Fire Alarm Telegraphs. No. 113,649.Patented April 11, 1871.

2 Sheets8heet 2. J. N. GAMEWELL.

Signal Box for Electra-Magnetic Fire Alarm Telegraphs.

No. 113,649. Patented-April 11, 1871.

timid fiat-c titlli ditto.

Letters Patent No. 113,649, dated April 11, 1871.

IMPROVEMENT'IN FIRE-ALARM TELEGRAPH APPARATUS.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern 7 Be it known that 1, JOHN N. GAMEWELL, ofHackensack, countyof Bergen, State of New Jersey, have invented a newand useful Improvement; in Automatic Signal-Boxes for Electro-MagneticFire-Alarm Telegraphs, of which the following is a specification,reference being had to the accompanying drawing forming part of thesame.

Figure 1 is a front elevation of a sigual-box containing my.improvement.

Figure 2 is a side elevation of the same box.

Figure 3 is a perspective view of the same box.

In order that the nature of my improvement may be the more readilyunderstood, before describing it I will refer to the construction andoperation of the signal-box and fire-alarm telegraph commonly in use.

The fire -alarm telegraph originated by Messrs. Farmer and Ghanning, ofMassachusetts, now commonly in use in this country, consists of a numberof telegraph stations located at suitable distances apart within citiesor villages, at points from which it may be thought advisable to givealarms of fire, all these stations being electro-telegraphica]lyconnected with a central station, or with each other, or both.

At each of the several stations within the electric circuit is placedwhat is called a signal-box, a piece of mechanism that is set in motionby a lever or crank, which winds up a spring or weight, the reaction ofwhich causes a movement of the mechanism that automatically breaks andcloses the electric circuit at stated intervals and a given number oftimes.

\Vithin the electric circuit are also placed a number of alarm-sounders,so constructed and connected with the electric circuit that the breakingof the circuit causes a hell or gong to be struck and thus an alarm tobe given.

The alarm-Sounders consist of an electro-magnet forming part of thecircuit with its armature, and a gong or hell so connected with thearmature oi' the magnet that when the circuit is broken and the armatureis thereby released from the magnet, its movement will set in motionmechanism that will strike a a blow upon the gong or hell.

The operation, therefore, of the signal-box is by breaking and closingthe circuit to give an audible signal upon the alarm-sounders.

This system is operated with a closed circuit-that is, the mechanism ofthe signal-boxes and the wires of the circuit are so constructed andarranged that the circuit is always closed, all the magnets in thecircuit being thereby, of cburse, charged, and having their respectivearmatures drawn toward them and there held, except at the instant when,by the operation of some one of the signal-boxes, the circuit is broken,

when, of course, all the magnets will be discharged,

causing alarms to be struck upon all the alarm-gongs or bellsconnected'with them.

Now, it is evident thatin the system arranged as above described thesignal-boxes are liable to interfere with each other and cause confusionin the giving of signals. Much difiiculty has been, in fact, practicallyexperienced on this account.

It at any time only a single signal-box is put in motion a regular andorderly signal will be given; but when two or more signal-boxes are setin motion simultaneously, or if, while one is giving a signal, anotheris set in motion, there must necessarily occur a confused mingling ofthe signals throughout the entire circuit, thus'tending to mislead andbewilder, instead of giving definite information.

The object of my invention is to obviate this difficulty, insuring theorderly giving of signals bypreventing the interfering of any signal-boxwith-any other in the circuit.

The method in which I accomplish this result I will proceed fully todescribe.

The general mechanism of the signal-box shown in the drawing it is notnecessary to describe particu-' larly, the same being well known and inextensive use.

The special devices comprising my improvements will be found, first, inthe novel construction and op eration of the break-circuit wheel; andsecond, in the combination with the armature of the magnet and thewinding-lever or crank of the signal-box of a device whereby thearmature is, by the movement of the lever, locked in the position itoccupies when attracted to the magnet, if, at the moment when e lever ismoved, the circuit is closed; and whereby t is locked away from themagnet if at the moment when the lever is moved thecircuit is broken,the wires of the circuit being so arranged that when the armature isattracted to the magnet the electric current passes necessarily over thebreak-circuit wheel; but when the armature is released from the magnetthe electric current is transmitted by a shorter route, cutting thebreak-circuit wheel out of the circuit.

All the circuit-breakers connected with signalboxes within my knowledgehitherto employed have been so constructed as when used in what iscalled the closed circuit to maintain the circuitconstantly closed,except when momentarily broken for the purpose of giving a signal, orwhen used in what is called the open circuit to maintain the circuitconstantly open, except when momentarily closed for the purpose ofgiving a signal.

My circuit-break wheel is so constructed and arranged in the circuitthat when standing at rest the circuit is closed but the moment itstarts to revolve the circuit is broken, thereby giving a signal, and remains broken until an instant before another signal is to be given, whenit is closed and instantly broken again to give the signal, and so onduring the entire revolution of the wheel, the circuit remaining openall the time, except momentarily, the instant before the giving ofsignaland when'the wheelcorne's to a state of rest, thus leaving thecircuit closed.

A is the circuit-wheel, made of metal, fixed upon a shaft, by which itis connected with a train of wheels and an escapem'ent, and to whichmotion is communicated by means of a main-spring, I), through anothershaft, a, to which it is attached, and upon which is a teeth in onegroup, and three in another, designed to signal the number 53.

The wire forming the circuit is severed, and the severed'ends areconnected one with each of the two metallic arms or springs c 0. Thesesprings are insulated and separated a little distance from each other,and, therefore, in order to close; the circuit it is necessary toestablish a connection between them. This is done across the face of theteeth upon the circuit-wheel whenever they are brought in contact withthe teeth.

The springs are secured'in such a. position that as the circuit-wheel isat rest they will be in contact with the first tooth of the group, andas the wheel is revolved they will successively come in contact with andpass over theface of all the teeth upon the wheel,

but will touch the wheel at no other point; and it is evident that thecircuit will be broken, and will remain broken and open during theentire revolution of the wheel, except during the momentary intervalswhen the springs are in contact with the teeth.

B B is an elect-ro-magnet placed in the. circuit formed by the wires 71.n -n" n".'

d is an armature, attached to an arm or lever, e, that is pivoted andswings upon the shaft f held between the brackets g g.

swings away from the magnet.

m is a spiral spring which acts to draw the outer endof the arm 0 intocontact with the end of the thumb-screw.

The ring 10 is made part of the circuit, the wires n n" being connectedwith.it upon opposite sides, as shown in the drawing.

O is a rodheld and arranged to slide vertically up and down-in holesmade in the ends of the brackets g g.

At'the top of this rod-is a hook, a, which projects over thewinding-lever a, with which itm'ay engage. Upon the back side of thisrod is a wedge-shaped lug or projection, s, so arranged with referenceto the end of the arm 0, which is also made wedge-shaped, that when thearm is in contact with the end of the thumb-screw j and the rod(] isforced downward, it, the lug s, will press against the outside of thearm and lock and hold. it in contact with the end of the thumbscrew, thearmature, of course, being at the same moment thereby locked out ofcontact with the magnet. But if the rod is forced downward while thearmature is drawn toward the magnet, and the outer end of the' lever eis swung to the opposite side of the lug s, then the armature will belocked to the magnet, and the outer end of the lever 0 will be lockedout of contact with the thumb-screwy.

t is a spiral spring on the rod G, acting to force it downward.-

D D are screw-cups forming part ofthe general circuit that runs throughand electricallyconnects all the stations and signal-boxes in a city ortown with each other andwith the battery.

From the screw-cup D a wire runs to and forms the 'coils of the magnet,thence back to the lower side of the ring 70. From the opposite side ofthe said ring the wire runs to one of the arms or springs, c, and fromthe other spring 0 down to and is connected with one of the brackets g,and thence back to the other screw-cup D. I

' Thus, as will be seen, while the-outer arm of the lever e is incontact with the end of the thumb-screw j the break-circuit wheel issubstantially cut out of the circuit, the direct and shortest route forthe electric current being through the ring is, the thumb-screw j, thearm e, the shaft f, the bracket g, and that portion of the wire nrunning from the said bracket to the screw-cup D. But when the arm 6 isnot in contact with the thumb-screwy the circuitawheel is necessarily inand forms part of the circuit, the electric current having to pass fromthe wire a to and through the magnet-coils, thence over the wire n tothe ring 70, thence over the wire n? to the spring 0, thence across theface of the circuit-wheel to the springc', and thence back to the cup D,over the wire a! The operation of a signal-box with'the above-describedform of break-circuit wheel and'loeking device is as follows, it beingassumed that all the signal-boxes in the circuit are similarlyconstructed and arranged:

Suppose all the boxes are-atrest and in the position shown in fig. 1.The circuit is now closed, and,

the armature being held in contact with the magnet, the outer end of thearm 0 will be swung away from contact with the thumb-screw j, and to theright of the lug s.

The book 0 resting upon the winding lever a, the rod Ois thereby held upso that the lug s is up out of the way of theend of the arm 0.

A signal is now to be given, and to that end the winding-lever a, isdepressed or pulled downward, winding up the maiuspring, the recoil ofwhich is to set the break-circuit wheel in motion.

As the lever descends, and before the break-circuit wheel is put inmotion, the rod 0 also descends, and, the-lug s passing down on theinner or left side of the outer end of the arm e, locks it in thatposition, so

that, 'until the rod is again raised, the lever cannot swing over intocontact with the thumb-screw j, and thus, during the entire revolving ofthe break-circuit wheel in giving and repeating the signal, as well whenthe circuit is broken as when closed, the break-circuit wheel will belocked in the circuit. As soon, however, as the circuit-wheel begins torevolve the circuit will be broken, and so remain, except momehtarily,while the springs are passing over the teeth on the periphery of thewheel; and, of course, during all the time that the circuit is brokenthe armaturedevers in all the other signal-boxes in the circuit will bein contact with the thumb-screws corresponding to j in this box, andthereby their several break-circuit wheels will, during the time, be outof the circuit.

Suppose, now, that while a signal isibeing given by this box the attemptshould be made to give a signal from any other in the circuit; it isplain that when the winding-lever of such box is depressed the rod 0,descending with it, will lock the armature-lever e in the position inwhich it is at the instant, and, as it is certain to be in contact withthe thumb-screw except while the springs c c are passing over the teethof the break-circuit wheel of this box, it is clear that unless thewinding-lever of the other box should be depressed at the precise momentwhen the springs c c are in contact with one of the teeth on this wheel,not only would no signal be given by the other box, but its ownbreak-circuit wheel would be securely locked out of the circuit, and soremain until the winding-lever should return to its normal position,and, by raising the rod 0, release the armature-lever; and so it isevident that while a signal is being given by any box in the circuit thechances are exceedingly small that it can be interfered with by anattempt to signal from any other box in the circuit, all derangement orconfusion of signals being thereby obviated.

The vast-importance and value of such a result in fire-alarmtelegraphing will be readily appreciated by all acquainted with thesubject.

I am aware that a patent was granted to James M. Gardiner, as assigneeof Moses G. Gram, December 28, 1869, for an improvement in signai-boxmechanism for fire-alarm telegraphs, in which there is described arotary circuit-wheel operated bya spring orweight, and connected withthe circuit by fingers resting on the face of the wheel, which'is madeto break the circuit by means of notches or insulators in its periphery.I do not claim, broadly, such a circuit-wheel.

Mr. Grams wheel, referred to, keeps the circuit at all times closed,both when at-rest and when in motion,

purpose of giving a signal. By my modification the circuit-wheel, asherein described, while it closes the circuit when atrest, as soon as itis put in motion it breaks the circuit and keeps it open until it hasper formed an entire revolution, except that it closes the circuit foran instant preparatory to breaking it for the purpose of giving asignal.

What I claim, therefore, and desire to secure by Letters Patent, is-

1. The circuit-wheel A, as a part of a signal-box mechanism forfire-alarm telegraphs, so constructed and arranged that, while it closesthe circuit when at rest, when put in motion immediately breaks thecircuit and keeps it open during an entire revolution, except for aninstant before each signal, when it'closes the circuit preparatory tobreaking it for the purpose of giving the signal, all arranged andoperating substantially as and for the purpose described.

2. The construction and arrangement of the circuitwires and lockingdevices herein described, whereby the motion of the winding-lever a inwinding'up the motor of the signal-box operates to lock thebreak-circuit wheelA in the electric circuit if at the moment when saidlever is moved the circuit is closed, and to lock said break'circuitwheel out of the electric circuit if at the moment when said lever ismoved the circuit is open, all constructed and arranged as described andshown, for the purpose specified.

" JOHN R. GAMEWELL.

Witnesses:

J. P. FITCH, WM. 0. Bnnmr.

except momentarily when it breaks the circuit for the Y

